added emulator for missing Iso10126 padding in .net core

Author: force-net

Blazer.Net.Tests/Blazer.Net.Tests.xproj

@@ -11,7 +11,7 @@
     <RootNamespace>Blazer.Net.Tests</RootNamespace>
     <BaseIntermediateOutputPath Condition="'$(BaseIntermediateOutputPath)'=='' ">.\obj</BaseIntermediateOutputPath>
     <OutputPath Condition="'$(OutputPath)'=='' ">.\bin\</OutputPath>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
   </PropertyGroup>
 
   <PropertyGroup>

Blazer.Net.Tests/EncryptionTests.cs

@@ -1,8 +1,11 @@
 using System;
+using System.IO;
+using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
 
 using Force.Blazer;
+using Force.Blazer.Encyption;
 
 using NUnit.Framework;
 
@@ -112,5 +115,38 @@ public void Invalid_Archive_If_Invalid_EncyptFull_Password()
 			var ex = Assert.Throws<InvalidOperationException>(() => IntegrityHelper.CheckCompressDecompress(data, blazerCompressionOptions, s => new BlazerOutputStream(s, new BlazerDecompressionOptions("1") { EncyptFull = true })));
 			Assert.That(ex.Message, Is.EqualTo("This is not Blazer archive"));
 		}
+
+		[Test]
+		public void Different_Paddings_Should_Not_Cause_Errors()
+		{
+			var data = Enumerable.Range(0, 100).Select(x => (byte)x).ToArray();
+			var pass = new Rfc2898DeriveBytes("test", 8, 4096);
+			var key = pass.GetBytes(32);
+			var aes = Aes.Create();
+			aes.Key = key;
+			aes.IV = new byte[16];
+			aes.Mode = CipherMode.CBC;
+#if NETCORE
+			aes.Padding = PaddingMode.PKCS7;
+#else
+			aes.Padding = PaddingMode.ISO10126;
+#endif
+			var memoryStream = new MemoryStream();
+			var cs = new CryptoStream(memoryStream, aes.CreateEncryptor(), CryptoStreamMode.Write);
+			cs.Write(data, 0, data.Length);
+			cs.Flush();
+			cs.Close();
+
+			var aes2 = Aes.Create();
+			aes2.Key = key;
+			aes2.IV = new byte[16];
+			aes2.Mode = CipherMode.CBC;
+			aes2.Padding = PaddingMode.PKCS7;
+			var cs2 = new CryptoStream(new MemoryStream(memoryStream.ToArray()), new Iso10126TransformEmulator(aes2.CreateDecryptor()), CryptoStreamMode.Read);
+			var data2 = new byte[128];
+			var len = cs2.Read(data2, 0, data2.Length);
+			Assert.That(len, Is.EqualTo(data.Length));
+			CollectionAssert.AreEqual(data, data2.Take(data.Length));
+		}
 	}
 }

Blazer.Net/Blazer.Net.csproj

@@ -65,6 +65,7 @@
     <Compile Include="Algorithms\BufferInfo.cs" />
     <Compile Include="BlazerFlushMode.cs" />
     <Compile Include="BlazerPatternedHelper.cs" />
+    <Compile Include="Encyption\ISO10126TransformEmulator.cs" />
     <Compile Include="Helpers\FileHeaderHelper.cs" />
     <Compile Include="Algorithms\StreamEncoderHigh.cs" />
     <Compile Include="Algorithms\Crc32C\Crc32C.cs" />

Blazer.Net/Blazer.Net.xproj

@@ -11,7 +11,7 @@
     <RootNamespace>Blazer.Net</RootNamespace>
     <BaseIntermediateOutputPath Condition="'$(BaseIntermediateOutputPath)'=='' ">.\obj</BaseIntermediateOutputPath>
     <OutputPath Condition="'$(OutputPath)'=='' ">.\bin\</OutputPath>
-    <TargetFrameworkVersion>v4.5.1</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
   </PropertyGroup>
 
   <PropertyGroup>

Blazer.Net/Encyption/DecryptHelper.cs

@@ -114,8 +114,15 @@ public static Stream ConvertStreamToDecyptionStream(Stream inner, string passwor
 			// zero. it is ok - we use random password (due salt), so, anyway it will be different
 			aes.IV = new byte[16];
 			aes.Mode = CipherMode.CBC;
+			var cryptoTransform = aes.CreateDecryptor();
+#if NETCORE
 			aes.Padding = PaddingMode.PKCS7; // here we will use such padding
-			return new CryptoStream(inner, aes.CreateDecryptor(), CryptoStreamMode.Read);
+			cryptoTransform = new Iso10126TransformEmulator(cryptoTransform);
+#else
+			aes.Padding = PaddingMode.ISO10126; // here we will use such padding
+#endif
+			aes.Padding = PaddingMode.PKCS7; // here we will use such padding
+			return new CryptoStream(inner, cryptoTransform, CryptoStreamMode.Read);
 		}
 	}
 }

Blazer.Net/Encyption/Iso10126TransformEmulator.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Security.Cryptography;
+
+namespace Force.Blazer.Encyption
+{
+	/// <summary>
+	/// This class emulates ISO10126 AES transform for .NET Core
+	/// </summary>
+	public class Iso10126TransformEmulator : ICryptoTransform
+	{
+		private readonly ICryptoTransform _origTransofrm;
+
+		/// <summary>
+		/// Constructor. Origignal transform should be aes with PKCS7 padding
+		/// </summary>
+		/// <param name="origTransofrm"></param>
+		public Iso10126TransformEmulator(ICryptoTransform origTransofrm)
+		{
+			_origTransofrm = origTransofrm;
+		}
+
+		/// <summary>
+		/// Dispose current transform
+		/// </summary>
+		public void Dispose()
+		{
+			_origTransofrm.Dispose();
+		}
+
+		int ICryptoTransform.TransformBlock(byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
+		{
+			return _origTransofrm.TransformBlock(inputBuffer, inputOffset, inputCount, outputBuffer, outputOffset);
+		}
+
+		byte[] ICryptoTransform.TransformFinalBlock(byte[] inputBuffer, int inputOffset, int inputCount)
+		{
+			var outBuffer = new byte[_origTransofrm.OutputBlockSize + inputCount];
+			var dummyBuffer = new byte[_origTransofrm.InputBlockSize + inputCount];
+			Buffer.BlockCopy(inputBuffer, inputOffset, dummyBuffer, 0, inputCount);
+			_origTransofrm.TransformBlock(dummyBuffer, 0, dummyBuffer.Length, outBuffer, 0);
+			Array.Resize(ref outBuffer, outBuffer.Length - outBuffer[outBuffer.Length - 1]);
+			return outBuffer;
+		}
+
+		int ICryptoTransform.InputBlockSize
+		{
+			get
+			{
+				return _origTransofrm.InputBlockSize;
+			}
+		}
+
+		int ICryptoTransform.OutputBlockSize
+		{
+			get
+			{
+				return _origTransofrm.OutputBlockSize;
+			}
+		}
+
+		bool ICryptoTransform.CanTransformMultipleBlocks
+		{
+			get
+			{
+				return _origTransofrm.CanTransformMultipleBlocks;
+			}
+		}
+
+		bool ICryptoTransform.CanReuseTransform
+		{
+			get
+			{
+				return _origTransofrm.CanReuseTransform;
+			}
+		}
+	}
+}